Background: Mutations in breast cancer susceptibility genes (BRCA1 and BRCA2) are associated with increased risks for breast, ovarian, and other types of cancer.
Purpose: To review new evidence on the benefits and harms of risk assessment, genetic counseling, and genetic testing for BRCA-related cancer in women.
Data sources: MEDLINE and PsycINFO between 2004 and 30 July 2013, the Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews from 2004 through the second quarter of 2013, Health Technology Assessment during the fourth quarter of 2012, Scopus, and reference lists.
Study selection: English-language studies about accuracy of risk assessment and benefits and harms of genetic counseling, genetic testing, and interventions to reduce cancer incidence and mortality.
Data extraction: Individual investigators extracted data on participants, study design, analysis, follow-up, and results, and a second investigator confirmed key data. Investigators independently dual-rated study quality and applicability by using established criteria.
Data synthesis: Five referral models accurately estimated individual risk for BRCA mutations. Genetic counseling increased the accuracy of risk perception and decreases the intention for genetic testing among unlikely carriers and cancer-related worry, anxiety, and depression. No trials evaluated the effectiveness of intensive screening or risk-reducing medications in mutation carriers, although false-positive rates, unneeded imaging, and unneeded surgeries were higher with screening. Among high-risk women and mutation carriers, risk-reducing mastectomy decreased breast cancer by 85% to 100% and breast cancer mortality by 81% to 100% compared with women without surgery; risk-reducing salpingo-oophorectomy decreased breast cancer incidence by 37% to 100%, ovarian cancer by 69% to 100%, and all-cause mortality by 55% to 100%.
Limitation: The analysis included only English-language articles;efficacy trials in mutation carriers were lacking.
Conclusion: Studies of risk assessment, genetic counseling, genetic testing, and interventions to reduce cancer and mortality indicate potential benefits and harms that vary according to risk.